You'll also have the nearly-naked Mileena from the beginning of the game. You'll unlock special costumes like the Raiden one in Challenge Tower, and as the guy in the video says, there will be a much bigger reward.

There's also rumors of klassic costumes for non-ninja characters, and the classic Cyrax and Sektor fatalities. Possibly Rain, Smoke, Noob and Ermac as well.

But with this new content comes dropped content, such as KOTH. That sucks :/